This project will continue its efforts towards development of a better understanding of the role of the immune response to microorganisms and its relationship to subsequent development of tumors. It proposes to prepare and characterize antigens from microorganisms and from human tumor cells and to perform primary binding types of tests with these components. Antigenic similarities between tumors and micro organisms have been found. It is possible that this type of sharing may be widespread and that "nonspecific" bacterial immunotherapy could be the outcome of shared or crossreacting immunologic stimuli. The antigenic relationships between antigens and tumors in microorganisms will be investigated with respect to developing new and specific approaches to immunotherapy. Immunoglobulins derived from guinea pigs and rabbits have anti-tumor activities against the line-10 guinea pig hepatocarcinoma. Antibodies may be a decisive factor in the development of resistance to this tumor. This will be studied with a view to developing rational methods of using antibodies to influence the pathogenesis of other tumors. Antibodies in normal and tumor bearer human sera were detected to a variety of bacterial, fungal and tumor-associated antigens. Sera from patients with leukemias and melanoma had a lower capacity to bind both microbial and tumor-associated antigen. Serial bleedings from patients with tumors will be studied to correlate changes in antibody levels and the presence of immune complexes with states of clinical disease. Information will be sought that can be of diagnostic and prognostic value.